242 



The ooeciutn. In the two cases hitherto found the gonozooecium is a mother- 

 zooecium situated on a single zocecium. It is covered by a zocecium of ordinary 

 structure, which only shows any difference in having a number of scattered pores 

 in its frontal wall which • does not seem to be specially strongly arched. Nor 

 does this coveiing-zooecium complete the branch, but may be succeeded by at 

 least one single zocecium. The aperture of the gonozooecium has a proximal 

 concave margin with acute corners. 



Form of colony. The alternation of uni- and bi-zooecial internodes is regulai*. 



Of this species I have examined some small colonies from Port Phillip Heads. 



Claviporella M. Gillivray, char, emend. 



The aperture is provided with a more or less deep sinus and with two robust, 

 strongly projecting hinge-teeth. Behind the aperture there is an inner cryptocyst 

 lamina and most often an oval, median pore, a remnant from the primary frontal 

 sinus. On either side of the aperture is a cylindrical acropetal spine, and the 

 pedal chamber, situated far proximally, is rudimentary and only communicates 

 with the zocecium through a single rosette-plate. The occlusion takes place in a 

 way similar to that in Scuticella. 



Claviporella geminata W. Thomps. 

 Catenicella geminata W. Thompson, Nat. Hist. Review, V, 1858. 



Proceed. Dublin Univ. Zool. and Botan. Associat. I, pag. 84, 

 PL VII, figs. 3, 4. 



(PI. XII, figs. 3 a, 3 b). 



The zooecia, which excluding the lateral chambers are rounded trapezi- 

 form, have a number of very small scatt^ed pores, and the sternal area gener- 

 ally shows 2—5, most often very small fenestrse. The aperture, the sinus of 

 which is twice as long as broad, is surrounded by 2 — 4 acropetalous spines of 

 very varying size, 2 distal, frontally directed ones and two lateral, the two former 

 of which diverge very little and may attain the length of the aperture on the 

 single zooecia. On the mother-zooecium they are but small, and this is always 

 true of the lateral ones, which are most often rudimentary or absent on the 

 single zooecia. On the proximal side of the sinus a more or less distinct sutural 

 line leads down to a small, very narrow pore, the margins of which are gener- 

 ally provided with small, dentiform processes. The two short, broad spines, 

 which meet in the sutural line, do not show any vestige of an inner cavity. 



The lateral chambers. The scapular chamber is everywhere, also on the ad- 

 zooecial side of the daughter-zooecium, developed as a somewhat compressed avi- 



